In this day and age when there is concern regarding the dependence on oil by a future motorized society, people are expecting that automobiles equipped with fuel cells, which use hydrogen as a fuel, will become popular. A fuel cell has a stack structure in which cells are stacked in series, and generates electrical power utilizing an electrochemical reaction between a fuel gas containing hydrogen and supplied to an anode and an oxidant gas containing oxygen and supplied to a cathode.
Fuel cells have various constraints in starting as compared to other types of power sources. The power generation efficiency of a fuel cell decreases due to a decrease in temperature or poisoning of an electrode catalyst, and therefore may become unable to supply a desired voltage/current and even unable to start equipment.
In light of such circumstances, an operation has been performed in which a fuel cell is started with a short supply of at least one of the fuel gas supplied to the anode and the oxidant gas supplied to the cathode, so that overvoltage in a part of the electrodes will increase and more heat will be generated, and thereby increasing the temperature of the fuel cell and restoring the electrode catalyst from poisoning, etc (hereinafter referred to as refresh operation) (see, for example, Patent Document 1 below).    Patent Document 1: JP2003-504807 T